Examine source code of Close Tab Context Menu

{
  "manifest_version": 3,
  "version": "111.0.0",
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "96": "images/icon96.png",
    "128": "images/icon128.png"
  },
  "action": {
    "default_icon": {
      "16": "images/icon16.png",
      "24": "images/icon24.png",
      "32": "images/icon32.png",
      "64": "images/icon64.png"
    },
    "default_title": "__MSG_appName__"
  },
  "permissions": [
    "storage",
    "contextMenus"
  ],
  "background": {
    "page": "background/background.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "closetab@barisderin.com"
    }
  }
}